##### Get a free home demo of LearnNext

Available for CBSE, ICSE and State Board syllabus.
Call our LearnNext Expert on 1800 419 1234 (tollfree)
OR submit details below for a call back

clear
searchtune

Mar 9, 2014

#### periodic table 1 to 30 plz give me with atmoic no. mass valency neutron proton and electronic configrution



sir these are given in book i want 21 to 30

Nov 26, 2014

#### WHAT IS THE POSTULATES OF RUTHERFORD'S ATOMIC THEORY?



Postulates of Rutherford nuclear model:
• Positive charge is concentrated in the center of the atom, called nucleus.
• Electrons revolve around the nucleus in ...

Feb 28, 2014



Ans:

## Ans:

According to JJ Thomson’s atomic model.
• An atom is a positively charg...

Nov 15, 2013

#### what are isotopes and isobars ? with examples and in simple Language



Ans:  Isotopes: The atoms which posses same atomic number (the atoms same element) but different mass number are called Isotopes.
Ex:

Jan 23, 2015

#### What is covalency and electrovalency?



Ans: Covalency: The number of electrons that an atom can shared to get ...

Feb 19, 2015

#### Examples of  isotopes and isobars.



Examples of Isotopes:
Isotopes of Hydrogen- Hydrogen – 1, Hydrogen – 2, Hydrogen - 3

Isotopes of Oxygen – Oxygen -16, Oxygen -17, Oxygen -18

Isotopes of Carbon &#...



Ans:
Draw backs of

Feb 23, 2014

#### pls answer fst



As because gold is very highly malleable then other if any other metal sheet is used the experiment is quite succesful

Feb 4, 2015

#### How to learn the atomic mass and valencies of elements easily?



For your grade you need to remember atomic masses of first 20 elements.